# Get mouseX and mouseY position with current transformation
**URL:** https://discourse.processing.org/t/get-mousex-and-mousey-position-with-current-transformation/34489
**Category:** Coding Questions
**Created:** [January 6, 2022, 6:20pm UTC](https://discourse.processing.org/t/get-mousex-and-mousey-position-with-current-transformation/34489 "2022-01-06T18:20:49Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@clankill3r](https://discourse.processing.org/u/clankill3r)
#### Post date: [January 6, 2022, 6:20pm UTC](https://discourse.processing.org/t/get-mousex-and-mousey-position-with-current-transformation/34489/1 "2022-01-06T18:20:49Z")
How can I get the mouse position (and where z hits the camera plane), inside the transformation.
So I need this before the `popMatrix()`.
```auto
void setup() {
size(600, 600, P3D);
}
public void draw() {
background(0);
translate(width/2, height/2, -100);
pushMatrix();
float rot_y = map(mouseX, 0, width, 0, TWO_PI);
rotateY(rot_y);
int dim = min(width, height) / 2;
noFill();
stroke(255);
box(dim);
// now what is the mouseX, mouseY position (and z, where it hits the near plane of the camera)
// with the current transformation?
// float x = ???;
// float y = ???;
// float z = ???;
popMatrix();
}
```
I tried things with getting the matrix and inverting it and multiplying the mouse coordinates with it, but no luck.
---
### Author:  [@Chrisir](https://discourse.processing.org/u/Chrisir)
#### Post date: [January 6, 2022, 6:42pm UTC](https://discourse.processing.org/t/get-mousex-and-mousey-position-with-current-transformation/34489/2 "2022-01-06T18:42:22Z")
I offer screenX and screenY which gives you the position of a 3D rotated point on the 2D screen so that you can check mouseX,mouseY against it
(modelX, modelY, modelZ does sth. similar)
---
### Author:  [@clankill3r](https://discourse.processing.org/u/clankill3r)
#### Post date: [January 7, 2022, 11:49am UTC](https://discourse.processing.org/t/get-mousex-and-mousey-position-with-current-transformation/34489/3 "2022-01-07T11:49:01Z")
No, it’s more complicated.
What I want is equal to unity’s ScreenToWorldPoint
> **[Unity - Scripting API: Camera.ScreenToWorldPoint](https://docs.unity3d.com/ScriptReference/Camera.ScreenToWorldPoint.html)**
> **[Calculation behind camera.ScreenToWorldPoint - Unity Answers](https://answers.unity.com/questions/1293942/calculation-behind-camerascreentoworldpoint.html)**
>
> Unity is the ultimate game development platform. Use Unity to build high-quality 3D and 2D games, deploy them across mobile, desktop, VR/AR, consoles or the Web, and connect with loyal and enthusiastic players and customers.
I made 2 attempts, I think I’m close, but this is above my head:
```auto
PVector screenPointToWorld(PVector sp) {
PGraphicsOpenGL _g = ((PGraphicsOpenGL)g);
// cam.worldToCameraMatrix?? Not sure about this one
PMatrix3D worldToCameraMatrix = new PMatrix3D(_g.camera);
worldToCameraMatrix.invert();
PMatrix3D world2Screen = new PMatrix3D(_g.projection);
world2Screen.apply(worldToCameraMatrix);
PMatrix3D screen2World = new PMatrix3D(world2Screen);
screen2World.invert();
float[] inn = new float[4];
inn[0] = 2.0f * (sp.x / width) - 1.0f;
inn[1] = 2.0f * (sp.y / height) - 1.0f;
inn[2] = _g.cameraNear;
inn[3] = 1.0f;
float[] pos = new float[4];
screen2World.mult(inn, pos);
int X = 0;
int Y = 1;
int Z = 2;
int W = 3;
pos[W] = 1.0f / pos[W];
pos[X] *= pos[W];
pos[Y] *= pos[W];
pos[Z] *= pos[W];
return new PVector(pos[X], pos[Y], pos[Z]);
}
```
```java
PVector screenPointToWorld(PVector sp) {
PGraphicsOpenGL _g = ((PGraphicsOpenGL)g);
// cam.worldToCameraMatrix?? Not sure about this one
PMatrix3D final_matrix = new PMatrix3D(_g.modelview);
final_matrix.apply(_g.projection);
final_matrix.invert();
float[] in = new float[4];
in[0] = sp.x;
in[1] = sp.y;
in[2] = sp.z;
in[3] = 1.0f;
/* Map x and y from window coordinates */
// in[0] = (in[0] - viewport[0]) / viewport[2];
// in[1] = (in[1] - viewport[1]) / viewport[3];
in[0] = in[0] / width;
in[1] = in[1] / height;
/* Map to range -1 to 1 */
in[0] = in[0] * 2 - 1;
in[1] = in[1] * 2 - 1;
in[2] = in[2] * 2 - 1;
float[] out = new float[4];
final_matrix.mult(in, out);
out[0] /= out[3];
out[1] /= out[3];
out[2] /= out[3];
return new PVector(out[X], out[Y], out[Z]);
}
```